A thin film transistor liquid crystal display (TFT-LCD) is a type of liquid crystal display, and is an active matrix type LCD. The thin film transistor liquid crystal display has features such as low radiation, low thickness and low power consumption, and is widely applied in various fields.
For the liquid crystal display, there is a problem that image contrast reduces while a viewing angle increases. Therefore there is a viewing angle problem in the liquid crystal display. In order to achieve a wide viewing angle display, both an in-plane switch (IPS) type liquid crystal display panel and a fringe field switching (FFS) type liquid crystal display panel have been developed. In the field of liquid crystal displays, FFS is a wide viewing angle technology developed to be applied in a large size panel and high definition desktop display and liquid crystal television. In the FFS technology, a transparent ITO electrode is used instead of an opaque metal electrode in the IPS. The width of the electrode and the distance between the electrodes are reduced. The liquid crystal molecules both between the electrodes and directly above the electrodes may oriented to rotate in the plane direction (parallel to a substrate) in response to the fringe electric field generated by electrodes between pixels in a same plane. Therefore light transmittance of a liquid crystal layer is increased. The FFS technology solves a problem of low light transmittance of the conventional IPS technology, so as to achieve high light transmittance with a wide viewing angle.
Referring to FIG. 1, FIG. 1 is a structural schematic diagram of electrodes in the existing IPS type liquid crystal display panel. In the IPS liquid crystal display panel, a horizontal electric field driving the liquid crystal is formed between a pixel electrode 1 and a common electrode 2. The driving voltage is increased according to the distance between the pixel electrode 1 and the common electrode 2. Sometimes the required driving voltage may be greater than a voltage that can be supplied by a driving chip. In such cases, the strength of the horizontal electric field formed by the driving chip is too weak to effectively drive the liquid crystals, leading to poor display quality.
Referring to FIG. 2, FIG. 2 is a structural schematic diagram of electrodes in a FFS liquid crystal display panel. In the FFS liquid crystal display panel, a pixel electrode 3 is located in an aperture region of a pixel unit in an entire plane structure, and forms a fringe electric field with a common electrode 4 above the pixel electrode 3. Although the pixel electrode 3 is transparent, the pixel electrode still absorbs 5% of transmitting light, leading to reduction in the light transmittance of the panel.